How does a financial model spanning 30 years account for the fact that money today is worth more than the same amount of money 20 years from now?

Financial models handle the changing value of money by using a method called discounting. Discounting is a math trick that shrinks future money so you can see what it is worth in today's dollars. This works because of a concept called the time value of money, which is the simple idea that a dollar in your hand right now is worth more than....